New Delhi: Got a roof to spare? Here, power your home at a low cost, and help bridge a power deficit at the same time. Rooftop solar power developers are approaching individual home owners to let them install rooftop solar units for free. The home will get cheaper power, and the developer will sell the surplus to the power grid.

“Why keep your rooftop vacant? If you don’t want to invest, give us your rooftop on lease," says Ketan Mehta, chief executive officer of Rays Power Infrastructure which has started executing projects in Jaipur under this model and is planning to scale up.

Here is what’s on offer: Give user rights for your rooftop for 25 years and get electricity for those many years cheaper than what you would get from the local utility. The developer will install the plant, power the home, and sell the surplus power to the grid.

The required investment will be roughly ₹ 2 lakh for a 2 kilo watt (KW) project and ₹ 10 lakh for a 15 KW project. Every KW requires 100 sq. ft space. Mehta said his company is planning to roll out the same model in the National Capital Region (NCR), Hyderabad, Pune and Nagpur this year.

“The return on investment is very good on such projects. One could recover the entire cost in five years," said Sunil Rathi, director of sales and marketing at Mumbai-based Waaree Energies Ltd. The Waaree, which has so far been focusing on industrial, institutional and government customers so far, is now getting into residential rooftop projects too.

In Maharashtra, power distribution firms charge ₹ 9-18 per kwh, making rooftop solar power an attractive proposition for home and commercial establishments, he said. Falling price of imported solar panels has pushed solar power tariffs below ₹ 5 a unit in new projects auctioned by various states, against ₹ 12 a unit in 2010.

You could also hire a project developer to install a plant at your own expense, saving on bills and selling the surplus. As part of home loans, many banks now cover residential rooftop plants as well.

Rooftop solar power, which is currently negligible, is expected to touch 40 gigawatt (GW) by 2022, when the government expects to have a total of 100 GW solar power capacity in place.

The country now has 6.7 GW solar power capacity, most of which are large scale projects. Solar industry players are now seeking projects on premises of government buildings, institutions, petrol pumps, hospitals and schools as well. The emphasis on renewable energy is part of India’s commitment to cut carbon emissions by 35% by 2030.

“The way policies are being framed by the government, reaching the 40 GW target in six years looks feasible," said Rathi.